This invention relates to devices for increasing the pitch diameter of a grooved pulley used in conjunction with a flexible power transmitting belt.
Devices for varying the pitch diameter of a pulley are well known. These devices generally comprise a pair of movable pulley flanges that are positionable relative to each other resulting in a variation in the pitch diameter as a function of the separation of the flanges. These variable pitch pulleys are costly, of complicated construction, and can only be used with "V" belts or belts of similar cross-section. No variable pitch devices are known that would accomodate other cross-sections such as round belts.
The present invention discloses a device for increasing the pitch diameter of a pulley having a V shaped groove, a semicircular groove or other configurations of grooves.